Heres a question I got asked the other day, ' if you are in a passenger jet at 30,000 feet that is pressurised, if you opened the door and jumped,WITH A PARACHUTE , could you survive the freefall, if you held your breath, until you deployed at 15000 ft? ' has anyone tried this ? well maybe not the passemger jet part

if you open the door of a presuurized cabin at that altitude, you wont have to jump...you and everything else will be sucked out so fast, your head may come off in the process...jet or not.

I jumpmastered a load ina B-26 to 21,500, and before jumping, I saw my brother's eyes had NO white in them, they were all blood colored, from lack of oxygen. I told the pilot to take it down, and would not allow anyone to jump, until we had adequate equipment.

I have also buddy breatehed with Darry Henry and Mari-Lou Macdonald in Florida, sharing one bottle between us. We each took one last gulp, and out the door at 22,120 ft. No problem.

All jumps higher than that up to 36916 I used a console and switched to a bailout bottle for freefall.

Holding your breath would be a waste of time, completely useless, and probably even a detriment. I believe it is possible for such a jump to be survivable. There are tabulated values for "time of useful consciousness" but indivudual variations are major. Haven't people climbed Mt. Everest (30,000 ft) without supplemental oxygen??

Some scenarios --

1) You don't lose consciousness... all is well 2) You do lose consciousness, but you wake up in time to pull 3) You lose consciousness, and don't wake up, but your cypres does...

I's relatively certain that altitude chamber tests of this have been done, I just don't know those specific results.

Ive been involved in many chamber tests, as high as 43000 feet. I was told by a physiologist that at 36,916, I would have had about 20 econds of useful consciousness, and then would likely have passed out. using that 20 seconds of freefall, would have brouht me into a better situatuion altitude wise, but what shape would I have been in at that time, I am not sure.The whole delay was 2 minutes and 29 seconds, so I still would have had 2 minutes....but in what condition?

Holding your breath would be a waste of time, completely useless, and probably even a detriment. I believe it is possible for such a jump to be survivable. There are tabulated values for "time of useful consciousness" but indivudual variations are major. Haven't people climbed Mt. Everest (30,000 ft) without supplemental oxygen??

Some scenarios --

1) You don't lose consciousness... all is well 2) You do lose consciousness, but you wake up in time to pull 3) You lose consciousness, and don't wake up, but your cypres does...

I's relatively certain that altitude chamber tests of this have been done, I just don't know those specific results.

Time of useful consciousness without oxygen at 30k is 30 seconds. At 28k it's 1 minute. At 26k 2 minutes:24k 3 minutes.

Time of useful consciousness without oxygen at 30k is 30 seconds. At 28k it's 1 minute. At 26k 2 minutes:24k 3 minutes.

Obviously there are several factors involved here . . . the amount of physical work you're doing at the time is pretty high up there. It is my understanding those times are for pilots at the controls of aircraft.

That said, it's interesting to note how quickly things "improve" as you decend, so in theory, if you can get out and start heading toward the earth with a minimum of exertion, you ought to be able to do it successfully, but I certainly wouldn't want to make that the normal practice -- that would just be foolish.

Obviously there are several factors involved here . . . the amount of physical work you're doing at the time is pretty high up there. It is my understanding those times are for pilots at the controls of aircraft.

That said, it's interesting to note how quickly things "improve" as you decend, so in theory, if you can get out and start heading toward the earth with a minimum of exertion, you ought to be able to do it successfully, but I certainly wouldn't want to make that the normal practice -- that would just be foolish.I only printed these numbers because I thought that they were of interest. High altitude jumps can be deadly. I would not recommend anybody doing them without getting properly trained.

Heres a question I got asked the other day, ' if you are in a passenger jet at 30,000 feet that is pressurised, if you opened the door and jumped,WITH A PARACHUTE , could you survive the freefall, if you held your breath, until you deployed at 15000 ft? ' has anyone tried this ? well maybe not the passemger jet part

Kevin Uliassi had his O2 regulator blow out at 30,000ft over northern India during his around-the-world balloon flight attempt in March 2000. He started an emergency descent (which is still slow in a 400,00 cu ft Rozier balloon) and stabilized at approx 22,000ft. He did not pass out. He was, however, in very good physical condition and had acclimatized to altitude over several weeks before his departure.

Your question ( although hypothetical) has to be looked at as not rapid decompression in an aircraft, because that opens up a whole new ballgame. If for example, a guy has a face mask and is breathing pure oxygen from a supply on board,, and then at an open door he jumps, he likely could make it to enough ambient air to breath. If however, he is breathing an air mixture inside the aircraft, there would have to be rapid decompression to get the door open, and the scenario changes bigtime. prolonged breathing with a face mask, he could have body saturation, and there would be enough oxygen in his blood to make it to a lower altitude, but there would be no saturation breathing the air mixture supplied in a pressureized aircraft...likely giving him a problem.

However, his biggest problem would come from the rapid decompression of the aircraft, with additional problems once he got out....IF he got out. Bill Cole

OK let me define the question, If the plane did suddenly decompress, And I survived, the initial shock of that, Would it be possible to go head down and get to a "safe" altitude to deploy my chute, lets say 15,000 ft , cos I dont want hypoxia.

Or am I going to get into difficulty just cos of the pressure differential? when the plane decompresses?

No oxygen saturation , just having a glass of wine, and some wally opens the door, and I have my chute near me, and can put it on, like I am a 13 yr old gymnast ,

with the scenario that you paint, wine, decompression, putting the chute on during decompression etc etc....I doubt very much you'd survive. I love a scenario with a risk, even an added risk, if I can plan it, but I wouldnt want to be part of your scenario at all. You have too many things against you before you begin. Bill Cole

interesting scenario but I'd agree with Bill that you propose TOO many variables to predict any success. Frankly, having watched most of the movies with bad and/or unrealistic skydiving scenes in them, Hollywood makes it appear possible.

'Wally' would likely never get the door open. If he did, decompression would be only one problem - the 5-600 mph wind blast would be quite another. If, and only if, you weren't torn apart or your rig torn from your body at those 'jumprun' speeds you're likely still a minute away from functionally useful air.

More likely, the pilot would see his little "door ajar" light and dive the plane till the wings broke off. He'd beat you to good air and you'd have much less chance of getting sucked into the engine.

Now, once the plane got down to a couple hundred mph and maybe 15,000 ft or so, I'd say "DB cooper already did that" but it's not been done since

...except at WFFC when they bring the 727 and "everybody does it".

-Dave PS: Bill Cole's done some 'strange' things involving parachutes ... trust him on this one

Without EVEN wanting to rehash all the REAL WORLD variables involved with High altitude jumping that I've posted in the safety forum I will just say that this "scenario" is a typical hollywood one. With that said, I will provide a link to an old but good early account of high altitude jumping and the difficulties involved. CLICK ME

Although I'm far, far away from being able to do a 30,000 foot jump this topic has always caught my interest. I'm always interested in the boundaries of the human body and oxygen deprevation is one of them.

My old man once held his breath for 3:00 on a bet in high school. He was a distance runner. I took this as a challenge around 16 years of age and hit 2:37. At the age of 18 I managed to hit 4:39 without breathing. I was loopy after that for a while -- I'll give you that. Now that I'm out of shape I can still do 3:00 because I'm accustomed to it I guess. I have no idea if this is a damned weird situation or not. I don't know anybody else that can do it personally but I know they're out there.

Around the era that I could hit 4:00 or higher consitently I was in Arizona at the Grand Canyon around 7,000 ASL and could run around and such with little difficulty.

Everest can be nailed without O2 from what I know and that's at 30,000 feet plus. Can't the same be done with skydiving? Granted, the percentage of skydivers capable of such things is probably a lower percentage than that of mountain climbers can but is there any real threat to a properly trained human being with good 02 utilization going out at 30,000 and having to wait 2:00 until they get to somewhat normal O2 saturation levels?

I admit I approach the subject from the wrong schooling. To hold your breath the key is not to saturate with 02 bur rather to breathe in preperation to deplete your blood stream of CO2. Your brain senses C02 levels to tell you when you're in trouble. Breathing hard does little to saturate your blood stream with 02 but very much to get out all the C02 that will turn on your instincts to breathe.

Do the two situations relate at all or is there something I'm missing?

Everest can be nailed without O2 from what I know and that's at 30,000 feet plus. Can't the same be done with skydiving?

Kind of like comparing apples and oranges if you ask me. Climbers aclimatize to their altitude over a very long period of time so that they can function up high, there is a physiological change in the body's ability to utilize O2. Even then summit attempts are quick to return back down as the health risks go up exponentially when at that altitude. Skydivers have absolutely no aclimatization period and are generally rapidly asending and decending which is why the bends and other physical ailments come into play.

In 1975 and again in 1977, I was training the Brigade of Special Forces in Ecuador, South America. The first time I stayed in the Capital city of Quito, which is 9500 ft above sealevel. I was starved of oxygen for the whole two weeks that I was there, and could hardly move.

I was able to lift my gear and get it on my back, but didnt have the strength to do up the snaps unless I gasped for some air for about 30 seconds.

After finally getting my gear on, I would slowly walk to the aircraft, an Israeli Arava, which looked like a small cigar with twin tail booms. I would then ( with great effort) climb on board, and off we would go to climb another 7500 ft higher.

For a 30 second freefall, we were jumping from17000 feet above sealevel, and this after living at 9500 feet, when we were not jumping.

I couldnt breathe on the ground, and gasped for air almost all the time. The city is built on hills, and to walk anywhere, it was a real job to climb the hills.

As we came in on jumprun, my interpreter Eduardo, would be running back and forth in the aircraft, giving the soldiers his last minute instructions. I was sitting near the door, not moving an inch.

The first stick of jumpers went out, Eduardo was sticking his head out the door, and he turned to me and said " all right on target".

In my situation, I mumbled "good for them" and waited until we had the plane again on jumprun, (Eduardo spotting) and when he said "Salto" I would get up, wheel around and fall out of the plane.

In freefall, it was like jumping at home, no problem, I would do all I had to do, and when I dumped, I would be back in the real world, unable to breathe again. I would fly my chute to whereever the target was, and huff and puff after landing, gasping for air.

Eduardo was so accustomed to the thin air, he and the others had no problems..their bodies were used to it....I was dead on my feet, but wouldnt lie down. Lying down took to much energy...which I didnt have.

The next time (1977) I had them do the jumping on the coast of Ecuador at Salinas, and between jumps I could stick my feet in the Pacific ocean. No breathing problems...but massive bacteria in the drinking water...Boy, was I sick and dehydrated when I finally got back to Toronto...4 days in hospital.

I have had 7 or 8 HAI courses (High Altitude Indoctrination), and each time was in a decompression chamber, to 35,000 or as high as 43,000 ft.

At 30K +, we were told to remove our oxygen masks, and given tests to perform. We ended up trying to put square pegs in round holes, writing our name was nothing more than a scribble, not resembling any letters of the alphabet...just a scribble. We were given items to hang on a board of hooks in designated places, and failed them all.

Once the mask was put back on our faces, we were fine, and it wasnt off for more than 1 minute for the test.The effects of hypoxia set in fast.

When I jumped from 36,916 ft, I prebreathed for 20 minutes before the aircraft even took off to help purge the nitrogen from my body. I continued to breathe ( demand regulator) until jumprun, and then I unhooked the console supply of oxygen and went on my bailout bottle, which is 2000 lbs of oxygen pressure, forcing it into my lungs.

This pressure reduces as the oxygen is used, and I come into the ambient air at 25,000 feet when the ground rush begins.I had a sensitive altimeter and a non sensitive altimeter and a stopwatch. The ground rush at that altitude is like jumping from 3000 feet and being at 500 feet.

It is necessary to forcibly exhale during the use of the bailout bottle, because you are exhaling against the 2000 lbs pressure.

The scenario of Neilly, is strictly HOLLYWOOD, and not in the least realistic.

It is akin to putting 6 bullets in a revolver including one blank, and then playing Russian Roulette..hoping to get that one blank.

Lack of oxygen in freefall at heights of 30,000 plus is no joke.

One last thing. During the first Gulf War, two Brit air crew ejecfted from their disabled jet, and were taken prisoner. Their photos were put on the front page of every newspaper, their faces black and blue. It declared that the Iraqis had beaten them.

When I saw the photos, I knew immediately the black and blue faces were from the ejection blast into the air. Its like being hit with a 2 X 4. Later, the news reports admitted that was the case.

One cannot leave an aircraft travelling at extremely high speeds without suffering some damage, especially to exposed parts of their bodies ( i.e. faces).

Neilly....tell your friend it just wouldnt work as your original scenario was put forth., Bill Cole D-41 Canada

LOL. Small world. I too have been to both of those locations in Ecuador. I had no problems in Quito but I thought salinas was too damn hot and humid. I also was able to climb Mt. Cotipoxi while I was there with Los Alpinistas de las fuerzas Especiales. I'm sure not much has really changed since you were there, it's pretty much the same just more people and buildings.

Between the real world tales from those of you sharing and the links I've followed, this has been one of the most entertaining and enlightening threads I've followed in a long while.

Neil (neilly), please let your friend know that he has helped bring out some very valuable discussions quite by accident and we're all better for it ... and that he would almost certainly enjoy the chance to get 'sucked out' at 3,000 ft on a a static line . His 'innocent hollywood whuffo scenario' has improved MY knowledge and the knowledge of many others.

OK so lets get this straight, watching a wally open the door of the plane whilst sipping my glass of wine, and then calmy putting on my rig,like thats gonna happen ( screeeeeeeeeeaaammmm!!!) IS not possible cos you are gonna end up sucked outta the plane , probably getting a severe beating and discarded into the sky, DAMN

BUT if i did Then I have to hold my breath, again probably not possible cos of the pressure difference, and I only have 20 seconds of useful conciousness, so I am gonna black out, DOUBLE DAMN

Then i am gonna fall, But if my rig has an AAD, and its set,chance in hell? like an icecubes , then my chute is gonna open and save my life, providing I get a clean opening, and I wake up to clear the twists etc.

Of course knowing my luck this is where I wake up to find either,

a) I am over the pacific, atlantic, a big piece of water, Cant swim, gonna sink

Even if you do pass out, you might wake up before...well...before your cypres fires. Happened to Tom Sanders on a big way jump from over 20K (passed out after standing up in line to exit, got carried out by the rush of jumpers). Course he had no cypres.